Fissured tile composed of glass fibers, gypsum cement, and aminealdehyde resin, and method of making same



f'Ross REFERENCE E A N Iv //.Dv

1953'" I. ARMSTRONG F'ISSURED TILE COMPOSED OF GLASS FIBERS, GYPSUM .i CEMENT, AND AMINE-ALDEHYDEZ RESIN, AND

'- METHOD OF MAKING SAME Filed Dec. 1950 WATER FOAMING AGENT CATALYST GLASS FIBERS ALPHA GYPSUM FOR FURTHER DRYING, PAINTING, enoovme OR THE LIKE.

MIXER- FOAMER FORMING TABLE CATALYST EXTRACTOR BELT f RIBBON BLENDER 6 uvmvrom Y ATTORN .6.

Patented Dec. 29, 1953 rFISSURED TILE COMPOSED 9F- GLASS FJBERS, GYPSUM CEMENT AND AMINE- -ALDEHYDE RESIN, T MAKING SAME tAND METHOD -OF Marshall C. 1 Armstrong, Hebron, Dhio; assignor {I120 wens -Gorn ng Fiberglas Corporation,- a cor- I peration of Delaware -1 Application December 9, I950; Serial l\[o. 200,077

r9. Claims. (01.1260-4'5) '1 This invention relates to'the manufacture of uacoustical and structuraltile and it relates more z-particularly to the manufacturebf'fissured-tile .zWhiCh may be used-in ceiling structures and the like. 5

max mum use of such high strength, inert, rot n --and fungus resistant, and incombustible fibers in "structural products-such as building tile and the like. A large proportion of the earlier in- An object ofthis'invention is to produce tile of sthvtype :described'which has attractively arvranged 'fissures 'onthe outersurface and is 'fis- 'qsured also "substantiallvthroughout the entire -':duce afissured tile of the typedescribedwhich has no definite pattern offissures within and on the surface thereof.

Another obiect'is-to produce an acoustical or structural tile of .the type"described=which-is ot-hydraulic cements as inorganic binders for -glass fibers. "In'the main',these have been found 'ssubstantially inorganic in nature such that it is -incombustible. and resistant to relatively high temperatures to which the acoustical -or "struc- ".tural tile might beexposed asan' incidence to normal use.

!-AZ fm'ther' obiect 'is' to produce annacoustical or structural tile of' the'type described-which does not require afacing and which may be fabrinated'with' color throughout the body thereof.

:Astill further object is to produce an. acoustithis invention.

*2 formanufacturing tileembodying "features of "Theuse of'glass fibers as a reinforcement in structural tile has been the subject of considerable research because of the desire to make vestigations -on-'the use of-such materials has 'centered about'the'development of an inorganic binder which would enable most effective use of the reinforcing glass fibers and which would permit use thereof in relatively high concentration.

Particular attention has been given to'the use --to be unsuitable because their short tanklife does not lend itself to present methods of application -'or integration of the binder onto glass -"wool fibers and because of difficulties encounteied in spraying such cement slurries. Further objection resides inthe lack of plastic flow in the -material during-:the curing period. Most important is thrdifficulty in' mixing hydraulic warm stmfit-ural'tile embodying fl' lyh h cements directly with glassfibers because of the vconcentratiorr ofreinforcing' glass fibers as com pared to products heretofore produced withsimi- :dartypes of bonding agents.

A stillfurther object isto-tproduceand to *pro- 3U relatively' large bulk volume of-the glass fibers coupled with'the lack of flow of the cement with minimum moisture: content with the result that it has been practically impossible heretofore to "Tide afmethod rm d e 'fi e tile" 0 11 "incorporate glass fibers in concentrations greater economical mass-production basis which requires -relatively 'rsimple" equipment 'and inexperienced than' io percent by weight. if more than 10 1 per cent'glass "fibers were incorporated in slurries cf "the type heretofore produced,- the resultin :mixtnrewouid be too-viscous tohandle.

"ithas-been -found-that mummrtiations as'highas '60 per cent by weight ca r high si c t o -5911 absorbing mefi :lbe incorporated-ass. reinforcement in tile emecientnand rwhiclrrmayi be readily :handlect and easily cut "to size .for lisealoneor-wittnmetal 40 s'plinestin 'efiectingran assembled relation.

These and other nbjectszrand-iadvantages-nf cthis .inventiontwilli hereinaftenappear land for qmrposes nf-jilustratiombutinot Df'liflfitfltiOD; an

mmbodiment 'of therinvention-sisishowns-inuthe wombination W1 "playing gypsum-cement as -the binding agent "when an .m' almy'de resin is employed 'in e cemen and compositionis deemed .to provide;increased volume without, in-

creasing the concentration or ratio of waterbevaond limits criesired for developing .,highest strength .of the cementand with -the resulting cdevelopment of voids. beneficial inacoustical in- -.sulationvor sstructural -tileof the type described.

thespracticeofsthisinvention; glass fibers are -incorporated -:in amounts ':ranging. from 20-60 cent-thy weight of 'the product. :tflt has been found further thatwhen the foamed v=1mixture.nf.mnitlaaldehyde resin and glass fibers :.are.:':mixed -*withthex-gypsumicement and cast smooth-r-zsm-tacesior. setting; fissures. are -iormednatmalls-bythediscontinuity .oi-the mass as the mass is formed into boards or molded into tile and allowed to set on such smooth surfaces. The fissures seem to form naturally throughout the body of the tile and in a non-uniform pattern on the surface of the tile so as to provide a useful insulation product having a very attractive appearance.

The possibility of incorporation of larger amounts of glass fibers than has heretofore been considered possible appears to result from the combination of increased volume of the other phases when foamed so as to minimize the effect of the large bulk volume of the glass fibers per unit area, without otherwise increasing the solids content, and the greater fluidity which results from the preferred use of gypsum characterized by low normal consistency (below 50), defined as the amount of water by weight required to produce a slurry of definite fluidity when mixed with 100 parts of the gypsum cement.

It has been found that the combination of elements herein described permits the incorporation of larger concentrations of reinforcin glass fibers notwithstanding the use of minimum amounts of water so that substantially the full complement of water required to set the g psum cement can be derived from the aqueous solution of the amide-aldehyde resin incorporated in an intermediate water soluble sta e of polymeric growth. stantiallv eliminated and optimum conditions for the production of a high strength product are caused to exist.

More specifically, in the practice of this invention, an amidggldghyje resin is foamed by 35 mnstantaziiaiia mn m aed eiiweifi merezun aete cammaseai an i; qmmjor bring ng a out the cure of the amide-aldehyde resin. The desired amount of W are introduced with continued mixing to continue the fo ming operation. The volume of the materials thus in orporated may be caused to increase 2 to fold under such conditions-the amount of foamin may be standardized from batch to batch by indications for 4.-

volume or the lik in the foaming chamber. wigs then introduced and well dis persed into the foamed composition and the mass is then transferred for sett n into suitable molds or rolled or otherwise formed into predeterm ned shapes or tiles on a smooth surfaced support. The mass sets rapidly and can usuallv be handled within ten to twenty minutes without the use of heat. althou h heat may be employed further to accelerate the set of the cement and the cure of catalvtically activated amide-aldehyde resin. When the surface upon which the mass is cast or deposited comprises a layer of a polyvinyl plastic, the cured section can be readily removed without the use of mold release compounds or materials, otherwise it is desirable to treat the surface for enabling rapid and easy release.

As thenmidemdehxdaxesin. use may be made of ureainmiamm r melamineinrmaldehxde resin. Dicyandiamide formahj ehyde resin has been found to be unsuitable for the purpose intended but there is reason to believe that other urea type resinous materials having a water soluble intermediate stage and a final curing stage may be used, such for example. as guanidine formaldehyde, big anidine formaldehyde and the like. Such resinous materials are best employed in amounts ranging from 1 part by weight amidealdehyde resin to 4 parts by weight gypsum. ce-

As a result, drying steps may be sub- 3 4 ment to 1 part by weight of the resin to 8 parts by weight of the gypsum cement. It is possible to use more resin up to equal parts by weight of the cement but no advantage is derived from such increased concentration while the cost is correspondingly raised.

Pc tassium sodium and ammonium salt resins and the sodium, potassium and ammonium j'siofsulphates have been used as the foa 2 a ent and it is preferred to employ dium laurvl sulphate (Duponal M. E). The amount of foaming agent is not critical but it is best to use from 0.5 to 3.0 per cent based upon a combined weight of the resin and water. One per cent by weight foaming agent is usually preferred in the usual practice in accordance with this invention.

The QWL advancing the reaction of the urea aldehyde resinous material may be selected of mm the type hydrochloric acid and sulfuric acid, or it may be selected Of rid-. eltsrcfdthsnuzeenammen em-.. .cmcridamnicaehleridemaina sl leridaiimem .ihs. l The amount of catalyst depends upon th'ty pe of resinous material employed and the type of catalytic agent. For example, amounts up to 0.5 to 2 per cent of the acid salts are employed particularly with urea aldehyde resins and up to 5 to 10 per cent of the inorganic acids may be employed especially with melamine-aldehyde resins. By way of illustration, catalysts ranging in amounts of 0.5 per cent mineral acids to 10 per cent by weight acid salts based upon the amount of resin may be used.

Gypsum cement best adapted for use in the practice of this invention comprises calcium sulphate hemihydrate (CaSO4. /2HzO) prepared by calcination of gypsum rock at approximately 250 F. under positive steam pressure in an autoclave without agitation. The resulting product, hereinafter referred to as alpha-gypsum, is usually in the form of relatively large dense, stubby shaped crystals which are non-porous in character. Because of their low water absorption and lessened surface area per unit weight, considerably less water is required to produce a slurry having fluidity comparable with gypsum cement otherwise prepared, as by the normal manner of calcining finely ground gypsum rock at 350 F. under atmospheric conditions. By the latter method, a non-uniform, absorbent, finely divided product is produced characterized by normal consistency of about to while alphagypsum has low normal consistency in the ran e of 40 to 50.

Thus less water is required to secure the desired fluidity in the use of alpha-gypsum and in many instances the water employed to dissolve the urea aldehyde type resin is sufficient to supply the 18.6 parts of water per parts by weight gypsum cement to form the cured dihydrate (CaSOrZI-lzO). In any event, the amount of water that need be supplied in addition to that incorporated with the resinous material is a minimum so that subsequent drying does not present a problem and the use of such lesser amounts of water per unit weight of cement over and above that theoretically required to set the cement enables the attainment of optimum conditions for developing highest strength in the end product. In the use of alpha-cement, water in amounts ranging from 40-50 parts per 100 parts of alpha-cement is all that is required. lit will be understood that this invention may also I I v I i i t to shorter lengths. Such fibers may be in the form of strands, arns mmdles d i is p ed to div'idual filaments with, but preferably without, size, or lubricant thereon.

The following examples are given by way of illustrating the manufacture of fissured acoustical tile and formulations which may be used therefor.

Example '1 Parts by weight Alpha-gypsum cement 4 Melamine aldehyde resin in water solution 1 Water 1.6 Glass wool fibers 4 Sodium lauryl sulphate .(Duponal M. E.) 11.026 37per centhydrochloric acid 0.02

Example 2 Parts by weight Alpha-gypsum cement 4 Urea formaldehyde resin (60 per cent solids in water solution) '1 Water 1.1 Continuous glass fibers out to about 1% inch lengths 4 Foaming agent 0.2

Ammonium chloride 0.05

Example 3 Parts by weight Alphaegypsum cement 4 Urea formaldehyde resin (67 per cent solids in water solution) 0.7 Water 1.75 Glass wool fibers 4' Sodium lauryl sulphate 0.025 Ammonium chloride 0.025

Example 4 Parts by weight Alph'a gypsum cement 4 Urea formaldehyde resin (50 per cent solids in water solution) 2 Water 0.6 Glass fibers 2 Foaming agent 41.05 Ammonium chloride 0.05

Example 5 Parts by weight Alpha-gypsum cement 4 Melamine aldehyde resin (60 per cent solids in water solution) 1 Water 0.6 Glass wool fibers 2.5 Foaming agent 0.025 3'? per cent sulfuric acid 0.02

1111a; themes or tablehydesrminis combined with the water, foaming agent Isodiumiauryl sulphate) and acid catalyst (hydrochiorio'acid .orzammnninm chloride) and agitated for mixing andfoaming. The full complement of glass fibers are the: incorporated izhe mixture with continued agitation zmtilthe foamed nompos'tion rises to a measured volume which is selected to be about 3-5 times the theoretical volume of the materials.

The gypsinn'icement is :then added with conthe vcement is fully dispersed. Since isettmg-starts immediately and will vtake place to the extent that the product can be handled within 10-20 minutes from the time the gypsum cementtls added-the mix is transferred mp'idly onto a forming "table where it can be molded, rolled or otherwise formed into desired sections. It is at this stage of thereaction, when themass-is spread out to set on a smooth surface. that fissures form in the face adjacent the smooth surface and also form throughout the body of the board or tile. If the mass is spread or deposited for setting upon a polyvinyl plastic surface, such as polyvinyl chloride and vinyl chloride-vinyl acetate copolymers, or polyvinylidine chloride, or polyvinyl acetal plastic in the form of films or sheetsylittle adhesion occurs between the set tile and the receivingsurface 'such that removal can be'very easily eifected. In the "event that the receiving surface is not formed of a vinyl plastic, the surface may be otherwise treated with suitable parting compounds.

It preferred to fabricate the materials from the time that theglass fibers are added by a substantially continuous technique which takes into consideration the critical nature of the materials and 'the time factor from the time that the gypsnmcement is incorporated whereby the product which 'is produced is substantially uniform ineharacter from day to day. A flow sheet for continuous manufacture is shown in Figure 4. Afterthe glass fibers have been introduced, the composition is incorporated in a ribbon type blender ormixer for receiving and properly distributing the gypsum. cement. The ribbon type blender feeds .a continuous stream of the blend to an extruding machine of the continuous type which extrndes the ribbon or sheet contoured to correspond toihe dimension of the tile or sheet to be produced .upon a continuous moving belt where the strip or -sheet is allowed to set. Vinyl or rubber belting may be used as the endless forming conveyor so that the set product may be removed without use-of releasing agents.

Setting occurs without heat in from 10-20 minutes depending upon the amount of moisture and the character or freshness of the gypsum cement. The'amide-aldeliyde resin is converted into an insoluble cured state in about 10 minutes in-the presence of the acidicvcnndensation catalyst hntthe rminset andrthe gypsum cement set can be accelerated hynxposure to elevated temperatures, suchas up :to 3008 F.

Aspreviousiy pointed out, it is desirable to keep the water content as low as possible commensurate with the desired fluidity of the mass and the development of optimum conditions for generating high strength properties in the end product. In each of the above formulations employing alpha-gypsum cement, 40-60 per cent water is the most that is needed based upon the weight of the gypsum cement. In the event that more water can be tolerated, the alpha-gypsum cement may be replaced in whole or in part with normal gypsum cement to produce a new product still having a relatively high concentration of glass fibers resulting from the greater mass area available because of the foaming technique. However, the strength properties and the drying characteristics of compositions wherein normal gypsum cements are substituted are markedly handicapped.

Acoustical tile prepared by either of the formulations of Examples 1-3 inclusive and by the steps later described, results in a highly fissured tile in which the fissures do not acquire a predetermined pattern or direction. The tile has a noise-reduction coefficient of about .55 or better. A tile having a thickness of about ,4 inch weighs about 1.5 pounds per square foot and has a. density of about 20.6 pounds per cubic foot. It enjoys a light reflect-ion of about 71 per cent when unpainted and absorption of less than 0.05 per cent moisture. It is able to withstand exposures up to 200 F. for an indefinite period of time and is Wholly incombustible.

It will be understood that inorganic coloring compounds and pigments may be incorporated as an element with the glass fibers in the batch to impart color characteristics throughout the formed structure or else an outer coating may be applied onto the fissured surface to give the desired colored appearance or other attractive features.

It will be understood that numerous other changes may be made in the etails of formulation and methods of handling without departing from the spirit of the invention, especially as defined in the following claims.

I claim:

1. Fissured tile consisting essentially of a mixture of glass fibers and a cement in which the fibers are present in amounts ranging from 20-60 percent by weight and in which the cement is formulated of a foamed amino-aldehyde resin solution in water and alpha gypsum cement present in the ratio of 1 part by weight resin to k8 parts by weight alpha gypsum.

2. Fissured tile consisting essentially of glass fibers in amounts ranging from 20-30 percent by weight of the final precinct bonded into a board having fissures on the surface and throughout the body thereof with a substantially inorganic cement formed of 1 part by weight amino-aldehyde resin foamed in water solution to 2-5 times its normal volume and containing water in about the amounts theoretically required to react for setting the gypsum cement and 4-8 parts by weight gypsum having a normal consistency less than 50.

3. Fissured tile consisting essentially of glass fibers in amounts ranging from 20-60 percent by weight of the final product intermixed with a binder formed essentially of 1 part by weight amino-aldehyde resin in water solution, 4-8 parts by weight alpha gypsum cement and a small amount of an agent for foaming the resin solution to 2-5 times its volume and an acidic catalyst for advancing the cure of the aminoaldehyde resin.

4. The method of manufacturing a fissured board of low density consisting essentially of glass fibers in amounts up to 20-60 percent by weight and a gypsum-amino-aldehyde resinous binder combination comprising the steps of foaming an amino-aldehyde resin in water solution, incorporating the glas fibers into the foamed resin while continuing the foaming thereof, mixing gypsum cement into the foamed composition in the ratio of 4-8 parts by weight cement to 1 part by weight resin, and forming the mass to desired shape whereupon the resineement binder sets while fissures automatically form in the surface and throughout the body thereof.

5. The method of manufacturing fissured tile having 20-60 percent glass fibers bonded with a cement formed of a combination of gypsum cement and an amino-aldehyde resin comprising the steps of foaming a mixture of an aminoaldehyde resin in water solution with a foaming agent and an acidic compound for curing the resin, continuing the foaming action while introducing the glass fibers, mixing in alpha gypsum cement in the ratio of 1 part resin to 4-8 parts cement, forming the mass to desired shape and allowing the mass to set while fissures automatically form on the surface and throughout the body thereof.

6. The method as claimed in claim 5 in which the foaming agent is a water soluble salt of a sulfonic acid present in amounts ranging from 0.5-3.0 percent by weight of the combined weight of water and resin.

7. In the method as claimed in claim 5 in which foaming i continued upon addition of the glass fibers into the foamed resin until the volume thereof is increased 2-5 times the natural volume of the materials therein. 1

8. The method as claimed in claim 5 in which the acidic catalytic compound is present in the ratio of 05-10 percent by weight of the aminoaldehyde resinous material.

9. The method as claimed in claim 5 in which the amount of water in the binder composition is maintained below percent by weight of the alpha gypsum cement.

MARSHALL C. ARMSTRONG.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,373,401 King Apr. 10, 1945 2,442,321 Cuppett May 25, 1948 2,451,446 Parsons Oct. 12, 1948 2,476,306 King July 19. 1940 FOREIGN PATENTS Number Country Date 231,242 Great Britain Mar. 30, 1925 61,242 Holland June 15, 1948 OTHER REFERENCES Koroseal Handbook of Tech. Info, pages 5 and 23, pub. 1942 by B. F. Goodrich Co. 

1. FISSURED TILE CONSISTING ESSENTIALLY OF A MIXTURE OF GLASS FIBERS AND A CEMENT IN WHICH THE FIBERS ARE PRESENT IN AMOUNTS RANGING FROM 20-60 PERCENT BY WEIGHT AND IN WHICH THE CEMENT IS FORMULATED OF A FOAMED AMINO-ALDEHYDE RESIN SOLUTION IN WATER AND ALPHA GYPSUM CEMENT PRESENT IN THE RATIO OF 1 PART BY WEIGHT RESIN TO 4-8 PARTS BY WEIGHT ALPHA GYPSUM. 